The aim of the proposed research is to further explore the relationship between structure and activity in the actinomycin series, and to synthesize analogues which might be more effective antitumor agents than actinomycin D. One approach to improved selectivity involves conjugation of suitable analogues to tumor-specific carrier proteins such as concanavalin A. The methods to be employed include total synthesis of actinomycin analogues, their purification by chromatographic methods, and comparative conformational studies by nuclear magnetic resonance. All actinomycin analogues produced in this project will be submitted to N.C.I. for evaluation of their antitumor efficacy.